As is known, large companies dedicated to the distribution and marketing of horticultural products are often equipped with lines that are at least partially automated and are capable of transporting, checking and/or packaging a large number of products of interest in the unit time.
Known lines are therefore already capable of performing several activities, such as for example washing, defect checking (and/or rejection or reprocessing of defective units), packaging and calibration, a term used to reference the selection of the horticultural products as a function of their dimensions.
It should be noted in this regard that calibration has a primary role in the automatic lines outlined so far, since even when they are intended for a single specific horticultural product (be it fruit or vegetable) they receive the goods to be processed directly from the harvesting fields and are therefore fed with indiscriminate masses of mutually heterogeneous products.
Along the lines, therefore, there are stations capable of selecting automatically the products as a function of the dimensions, in order to assign them to different downstream stations (which are thus fed with mutually homogeneous products) and/or package them in different packages as a function of their size.
Indeed due to the importance of this function (performed by stations that perform the desired selection mechanically or electronically), and due to the heterogeneous nature of the goods, the most modern lines have, upstream of the calibration station, an additional (“pre-calibration”) station, which performs a preliminary selection of the horticultural products.
In greater detail, and with specific reference to lines dedicated to cherries, in the pre-calibration stations a stream of water that entrains with it the cherries to be selected affects a plurality of suspended cylinders, which are mutually parallel and rotate about their own axis.
The cylinders are inclined (downstream) and appropriately mutually spaced and contoured, so that a longitudinally oriented slot is formed between each pair of adjacent cylinders.
In this manner, as soon as the stream strikes the cylinders, the water, any leaves, stems and other debris fall directly below; minimum-size cherries (i.e., the only ones which, due to their small dimensions, are able to pass through the slot) may further fall slightly further on. Vice versa, the largest cherries continue their travel, sliding along the lateral surfaces of the cylinders (which rotate indeed to facilitate advancement) until they fall downstream of said cylinders.
Thus, in addition to removing leaves and other debris, the station performs a first division of the cherries into two groups (indeed as a function of dimensions), each of which is collected in a respective tank filled with water, which is of course arranged below the cylinders and makes the respective cherries available to the actual calibration stations.
However, this constructive solution is not devoid of drawbacks.
It should in fact be noted that in known pre-calibration stations the rotation of the cylinders is entrusted to a motor that actuates a series of gears, with which respective pins which protrude coaxially from the end directed downstream of the cylinders.
This configuration forces the need to keep the cylinders at a vertical level that is significantly higher than the level at which the upper edge of the collection tanks is located.
Only in this manner the motor and the gears that are responsible for the movement of the cylinders (indeed located below the lower ends of said cylinders) can find an adequate placement without having to be themselves immersed in the water of the tanks (an obviously unacceptable condition).
However, this entails a considerable leap for the cherries, when they fall from the slot or from the lower end of the cylinders into said tanks.
Although this usually is not a problem (due to the low weight) for the smallest cherries, the excessive leap is instead a highly unwelcome drawback for larger ones (which, as shown, slide along the entire length of the cylinders and fall beyond).
Larger cherries can in fact fall onto other cherries that are floating in the tank, bruising each other or otherwise becoming damaged, causing in any case a degree of defectiveness that is now unacceptable.